77 lines
2.1 KiB
ReStructuredText
77 lines
2.1 KiB
ReStructuredText
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Implementing Wakeup or Clone
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============================
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As explained in the
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`restrictions for entity classes in the manual <http://www.doctrine-project.org/documentation/manual/2_0/en/architecture#entities>`_,
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it is usually not allowed for an entity to implement ``__wakeup``
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or ``__clone``, because Doctrine makes special use of them.
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However, it is quite easy to make use of these methods in a safe
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way by guarding the custom wakeup or clone code with an entity
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identity check, as demonstrated in the following sections.
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Safely implementing \_\_wakeup
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------------------------------
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To safely implement ``__wakeup``, simply enclose your
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implementation code in an identity check as follows:
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::
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<?php
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class MyEntity
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{
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private $id; // This is the identifier of the entity.
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//...
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public function __wakeup()
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{
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// If the entity has an identity, proceed as normal.
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if ($this->id) {
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// ... Your code here as normal ...
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}
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// otherwise do nothing, do NOT throw an exception!
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}
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//...
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}
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Safely implementing \_\_clone
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-----------------------------
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Safely implementing ``__clone`` is pretty much the same:
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::
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<?php
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class MyEntity
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{
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private $id; // This is the identifier of the entity.
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//...
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public function __clone()
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{
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// If the entity has an identity, proceed as normal.
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if ($this->id) {
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// ... Your code here as normal ...
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}
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// otherwise do nothing, do NOT throw an exception!
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}
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//...
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}
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Summary
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-------
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As you have seen, it is quite easy to safely make use of
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``__wakeup`` and ``__clone`` in your entities without adding any
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really Doctrine-specific or Doctrine-dependant code.
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These implementations are possible and safe because when Doctrine
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invokes these methods, the entities never have an identity (yet).
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Furthermore, it is possibly a good idea to check for the identity
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in your code anyway, since it's rarely the case that you want to
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unserialize or clone an entity with no identity.
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